SUMMATIVE ASSESSMENT - I (2011) Lakdfyr ijh{kk&i (2011) 570037 SCIENCE / fokku Class X / & X Time allowed : 3 hours Maximum Marks : 80 fu/kkzfjr le; % 3?k.Vs vf/kdre vad % 80 General Instructions : i). The question paper comprises of two sections, A and B. You are to attempt both the sections. ii). All questions are compulsory. iii). There is no overall choice. However, internal choice has been provided in all the five questions of five marks category. Only one option in such questions is to be attempted. iv). All questions to section A and all questions of section B are to be attempted separately. v). Questions 1 to 4 in section A are one mark questions. These are to be answered in one word or one sentence. vi). Questions 5 to 13 in section A are two marks questions. These are to be answered in about 30 words each. vii). Questions 14 to 22 in section A are three marks questions. These are to be answered in about 50 words each. viii). Questions 23 to 25 in section A are five marks questions. These are to be answered in about 70 words each. ix). Questions 26 to 41 in section B are multiple choice questions based on practical skills. Each question is a one mark question. You are to select one most appropriate response out of the four provided to you. a lkeku; funsz k % (i) bl iz u i= dks nks Hkkxksa, Hkkx v vksj Hkkx c esa ckavk x;k gsa vkidks nksuksa Hkkxksa ds iz uksa ds mrrj fy[kus gsaa (ii) lhkh iz u vfuok;z gsaa (iii) iwjs iz u i= ij dksbz p;u izkir ugha gs ijurq ikap&ikap vadks ds ikwap iz uksa esa Hkhrjh p;u fn;k x;k gsa bu iz uksa es vki dsoy,d Hkhrjh p;u dks mrrj fy[kus ds fy, pqu ldrs gsaa (iv) vkidks Hkkx v vksj Hkkx c ds lhkh iz uksa ds mrrj i`fkd&i`fkd fy[kus gksaxsa (v) Hkkx v ds iz u la[;k 1 ls 4 ds iz u,d&,d vad ds gsaaa buds mrrj,d kcn vfkok,d okd; esa nsaa (vi) Hkkx v ds iz u la[;k 5 ls 13 ds iz u nks&nks vadksa ds gsaa buds mrrj yxhkx 30&30 kcnksa esa nsus gsaa (vii) Hkkx v ds iz u la[;k 14 ls 22 ds iz u rhu&rhu vadksa ds gsaa buds mrrj yxhkx 50&50 kcnksa esa nsus gsaa (viii) Hkkx v ds iz u la[;k 23 ls 25 ds iz u ikap&ikap vadksa ds gsaa buds mrrj yxhkx 70 kcnksa esa nsus gsaa (ix) Hkkx c ds iz u la[;k 26 ls 41 ds iz u iz;ksxkred dks ky ij vk/kkfjr cgqfodyih iz u gsaa izr;sd iz u,d vad dk gsa fn, x;s pkj fodyiksa esa ls vkidks dsoy,d lcls mi;qdr fodyi pquuk gsa SECTION-A / ' ' 1. Explain the term rancidity. Page 1 of 17

2. An element A forms two oxides AO and AO 2. The oxide AO is neutral whereas the oxide AO 2 is acidic in nature. Would you call element A a metal or a non-metal? A AO AO 2 AO AO 2 3. State the property of black surface which is used in the working of solar heaters. 4. State the relationship between 1 volt and 1 joule. 5. What are the products formed when magnesium metal reacts with water? Why do the pieces of metal start floating during the reaction? 6. It is advised to pour acid into water rather than water to acid for the dilution of acids. Why? 7. What is meant by a skeletal chemical equation? Using suitable chemical reaction, differentiate between a skeletal chemical equation and balanced chemical equation. 8. When a green iron compound is heated strongly, its colour changes to black and odour of burning sulphure is given out. Name the compound State the type of reaction Write the chemical equation involved Page 2 of 17

9. Mention the two main components of the transport system in plants. State one function of each one of these components. 10. Large scale use of nuclear energy becomes prohibitive due to some hazards. State any two major hazards associated with a nuclear power plant. 11. Aluminium wire has radius 0.25 mm and length of 75 m. If the resistance of the wire is 10, calculate the resistivity of aluminium. 0.25 mm 75 mm 10 12. A student performs an experiment to study the magnetic effect of current around a current carrying straight conductor with the help of a magnetic compass. He reports that (i) (ii) the degree of deflection of the magnetic compass increases when the compass is moved away from the conductor. the degree of deflection of the magnetic compass increases when the current through the conductor is increased. Which of the above observations of the student appears to be wrong and why? (i) (ii) 13. How would the reading of (V) change if it is connected between B and C? Justify your answer. Page 3 of 17

(V) B C 14. 15. State what is observed when water is added slowly to a small amount of calcium oxide (quick lime). Name the type of reaction that takes place and write a balanced chemical equation for the reaction involved. The products obtained on electrolysis of concentrated aqueous solution of a substance X are NaOH, Cl 2 and H 2. Name the substance X. What is the special name of this process and why? Which gas is liberated at anode? List one commercial use of NaOH. X NaOH, Cl 2 H 2 X NaOH 16. Equal lengths of Mg ribbon are taken in test tubes A and B. Hydrochloric acid is added to test tube A. While acetic acid is added to test tube B. In which case the reaction Page 4 of 17

would occur more vigorously and why? Write the chemical equations for reactions in test tube A and B. Fresh milk has a ph of 6. How will the ph change as it turns into curd? Give reason for your answer. A B A B A B ph 6 ph 17. Which hormone is responsible for the changes noticed in males at puberty? Deficiency of which hormone leads to dwarfism. Name the hormone which is injected to a diabetic patient. 18. Which hormone is secreted when growing plants detect light? How does this hormone help the shoot to bend towards light? 19. What are the factors that should be taken into consideration for selecting a source of energy? List any three. 20. A piece of wire of resistance 20 is drawn out so that its length increases to twice its original length. Calculate the resistance of the wire in the new situation. 20 21. What is the total resistance of n resistors each of resistance R connected in : (i) Series (ii) Parallel? Page 5 of 17

Calculate the resultant resistance of 3 resistors 3, 4 and 12 connected in parallel. R n (i) (ii) 3, 4 12 22. (i) What precautions should be taken to avoid the overloading of domestic electric circuits? (ii) An electric oven of 2 kw power rating is operated in a domestic electric circuit of that has a current rating 5A. If the supply voltage is 220V, what result do you expect? Explain. (i) (ii) 2 kw 220V 5A 23. Write the electron dot structure for calcium and oxygen. The atomic numbers of calcium and oxygen are 20 and 8 respectively. Show the formation of calcium oxide by the transfer of electrons. Give reason for the following: (i) Ionic compounds are hard solids (ii) Ionic compounds conduct electricity in the molten state but not in the solid state. (i) (ii) 20 8 OR Describe in brief an activity to investigate the conditions under which an article made of iron rusts. List any four methods used for the prevention of rusting of iron. 24. (i) Leaves of a healthy potted plant were coated with vaseline to block the stomata. Will this plant remain healthy for long? State three reasons for your answer. (ii) State any two differences between autotrophic nutrition and hetrotrophic nutrition. (i) Page 6 of 17

(ii) OR (A) Draw a sectional view of the human heart and label on it the following parts : (i) Aorta (ii) Pulmonary arteries (iii) Vena cava from upper body (iv) Left ventricle (B) Why is double circulation of blood necessary in human beings? (A) (i) (iii) (ii) (iv) (B) 25. Name the scientist who discovered that a moving magnet can be used to generate electric current. With which name is this phenomenon known? Two coils 1 and 2 of insulated copper wire having large but different number of turns are wound over a cardboard cylinder. Coil 1 is connected to battery and a plug key. Coil 2 is connected to a galvanometer. How will the galvanometer reading change when? (i) (ii) key is plugged in and key is taken out. Give reason for your answer. Name and state the rule used for determination of direction of induced current due to a changing magnetic field and give one practical application of this phenomenon in everyday life. 1 2 2 1 (i) (ii) Page 7 of 17

OR Consider a circular loop of wire lying in the plane of the paper. Let the current pass through the loop clockwise. With the help of a diagram explain how the direction of the magnetic field can be determined inside and outside the loop. Name the law used to find the direction of magnetic field. Draw a diagram to represent a uniform magnetic field in a given region. List two properties of magnetic field lines. SECTION B / 26. A student was observing a ph chart. He observed that the two colours at the extreme ends of the ph chart are : red and green red and blue ' ' green and blue orange and green ph ph 27. The ph value of a solution is 6. What is the colour developed when a student adds 3 drops of universal indicator in the solution Red Blue Green Orange ph 6 Page 8 of 17

28. Four students performed the reactions of dil Hydrochloric acid and a solution of sodium hydroxide with zinc metal and solid sodium carbonate separately. They reported the possible reaction by ( ) and no reaction by (X). In which of the following sets all observations are correct? Set HCl + Zn HCl + Na 2 CO 3 NaOH + Zn NaOH + Na 2 CO 3 ( ) ( ) 29. When iron nail is kept in copper sulphate solution for about 3-4 hours, it is observed that Set HCl + Zn HCl + Na 2 CO 3 NaOH + Zn NaOH + Na 2 CO 3 only the tip of nail get the coating of copper only the bottom of the nail get the coating of copper whole nail get the coating of copper no coating is formed on the nail 3-4 30. When aqueous solutions of sodium sulphate and barium chloride are mixed together we find Page 9 of 17

that the reaction mixture : turns red forms a white precipitate forms a yellow precipitate remains colourless 31. In an experiment a student is using following measuring instruments having 50 division each on their scales Ammeter (0-5A) Voltmeter (0-10V) The respective least count of these instruments are 0.2A ; 0.2V 0.1A ; 0.1V 0.2A ; 0.1V 0.1A ; 0.2V (0-5A) (0-10V) 50 0.2A ; 0.2V 0.1A ; 0.1V 0.2A ; 0.1V 0.1A ; 0.2V 32. A student draws the circuit diagram as shown. The parts labelled X, Y and Z respectively are : Page 10 of 17

Ammeter, resistor, voltmeter Ammeter, voltmeter, resistor Voltmeter, resistor, ammeter Voltmeter, ammeter, resistor X, Y Z 33. The following circuit diagram shows the experimental set up for the study of dependence of current on potential difference. Which two circuit components are connected in series. battery and voltmeter ammeter and voltmeter ammeter and rheostat resistor and voltmeter Page 11 of 17

s 34. To determine the equivalent resistance of two resistors in parallel combination a circuit is shown below. The component of the circuit whose terminals are wrongly connected is : rheostat cell volt meter ammeter 35. Two resistances R 1 and R 2 are to be connected in series combination. Out of the following the correct combination is shown in : Page 12 of 17

only A only B only C all of them A, B and C R 1 R 2 36. A B C A, B C Steps involved to test the presence of starch in a leaf are shown by figure (i), (ii), (iii) and (iv) which are not in correct sequence? Which one of the following is the correct sequence for the process to test the starch? Page 13 of 17

(i), (iii), (ii) and (iv) (i), (ii), (iv) and (iii) (i), (iv), (iii) and (ii) (ii), (iii), (i) and (iv) (i), (ii), (iii) (iv), Page 14 of 17

(i), (iii), (ii) (iv) (i), (ii), (iv) (iii) (i), (iv), (iii) (ii) (ii), (iii), (i) (iv) 37. A destarched leaf of a potted plant is partially covered with black strip of paper on the upper and lower surfaces as shown in the figure and kept in sunlight. The starch test was performed after this. What will be the colour of the regions marked as A and B in the leaf? A-blue black, B-pale A-green, B-pale A-pale, B-blue black A-blue black, B-green A B A - B - A - B - A - B - A - B - 38. Temporary mount of a peel is made in : Alcohol Water Glycerine Acetone Page 15 of 17

39. Coverslip is put on the slide very gently to avoid : Entry of air bubbles Crushing of the material Oozing of glycerine None of these 40. Observe the following set up and choose the right reason as to why water has not risen in the delivery tube. The set up is airtight. Beaker has coloured water. CO 2 is not being absorbed O 2 is not available to seeds for respiration CO 2 Page 16 of 17

O 2 41. The correct set of three precautions for setting up the experiment to demonstrate that CO 2 is evolved during respiration is : Thread holding KOH test tube, Airtight flask, delivery tube above water surface in the beaker Flask has just germinated seeds, Airtight set up, delivery tube dip in water in beaker. Flask has seeds covered with water, Airtight set up, KOH test tube held by a thick wire. Just germinated seeds under water in the flask, delivery tube above water level, Thread holding KOH test tube. KOH CO 2 KOH KOH Page 17 of 17